75 research outputs found

    Dynamic Access Control In Cloud Computing Using Encryption/Decryption

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    Cloud computing has emerged as one of the most important paradigms in the IT industry for last few years. In general data owners and service providers are not in the same trusted domain in cloud computing. Service providers should not be a trusted one anyhow they are all third party. The system focuses on a novel technique to Hierarchical Attribute Set Based Encryption (HASBE); it is driven by the Cipher Policy attribute based encryption (CPABE) with a  hierarchic al structure of cloud users. Cloud computing is known as “Utility”. Cloud Computing enabling users to remotely store their data in a server and provide services on demand. Since this new computing technology requires user to entrust their valuable data to cloud providers, there have been increasing security and privacy concerns on outsourced data. We can increase security on access of the data in the cloud. Morever we can provide encryption on the data so third party can not use the data. In this paper we will be reviewing various encryption based access control model for enhancing cloud security along with their limitations. We will be concluding with a proposed access control model to enhance cloud security. The proposed work focuses CRM (Customer Relationship Management) for business model that is driven by the category of Software as a Service (Saas) method in cloud. Using this scheme it achieves the flexible, scalable and fine grained access control of data. It also achieves high secure and effective user revocation in cloud environment.

    Angiosomes of medial cord of brachial plexus

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    This anatomical study analyzed the neurovascular relationship of the brachial plexus. Ten formalized specimens of brachial plexuses were examined after injection of lead oxide in to the subclavian artery. The vascular, anatomical features of the brachial plexus were documented .The specimens were analyzed by dissection method, subjected for microscopic study. The vascular supply was markedly rich, often with true anastomotic channels found within the nerves. There was much variation in supply, depending on the branching pattern of subclavian artery

    On the elastic anisotropy of the entropy-stabilized oxide (Mg, Co, Ni, Cu, Zn)O compound

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    In this paper, we study the elastic properties of the entropy-stabilized oxide (Mg, Co, Ni, Cu, Zn)O using experimental and first principles techniques. Our measurements of the indentation modulus on grains with a wide range of crystallographic orientations of the entropy-stabilized oxide revealed a high degree of elastic isotropy at ambient conditions. First principles calculations predict mild elastic anisotropy for the paramagnetic structure, which decreases when the system is considered to be non-magnetic. When the antiferromagnetic state of CoO, CuO, and NiO is accounted for in the calculations, a slight increase in elastic anisotropy is observed, suggesting a coupling between magnetic ordering and the orientation dependent elastic properties. Furthermore, an examination of the local structure reveals that the isotropy is favored through local ionic distortions of Cu and Zn - due to their tendencies to form tenorite and wurtzite phases. The relationships between the elastic properties of the multicomponent oxide and those of its constituent binary oxides are reviewed. These insights open up new avenues for controlling isotropy for technological applications through tuning composition and structure in the entropy-stabilized oxide or the high-entropy compounds in general

    Early social distancing policies in Europe, changes in mobility & COVID-19 case trajectories: insights from Spring 2020

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    Background Social distancing have been widely used to mitigate community spread of SARS-CoV-2. We sought to quantify the impact of COVID-19 social distancing policies across 27 European counties in spring 2020 on population mobility and the subsequent trajectory of disease. Methods We obtained data on national social distancing policies from the Oxford COVID-19 Government Response Tracker and aggregated and anonymized mobility data from Google. We used a pre-post comparison and two linear mixed-effects models to first assess the relationship between implementation of national policies and observed changes in mobility, and then to assess the relationship between changes in mobility and rates of COVID-19 infections in subsequent weeks. Results Compared to a pre-COVID baseline, Spain saw the largest decrease in aggregate population mobility (~70%), as measured by the time spent away from residence, while Sweden saw the smallest decrease (~20%). The largest declines in mobility were associated with mandatory stay-at-home orders, followed by mandatory workplace closures, school closures, and non-mandatory workplace closures. While mandatory shelter-in-place orders were associated with 16.7% less mobility (95% CI: -23.7% to -9.7%), non-mandatory orders were only associated with an 8.4% decrease (95% CI: -14.9% to -1.8%). Large-gathering bans were associated with the smallest change in mobility compared with other policy types. Changes in mobility were in turn associated with changes in COVID-19 case growth. For example, a 10% decrease in time spent away from places of residence was associated with 11.8% (95% CI: 3.8%, 19.1%) fewer new COVID-19 cases. Discussion This comprehensive evaluation across Europe suggests that mandatory stay-at-home orders and workplace closures had the largest impacts on population mobility and subsequent COVID-19 cases at the onset of the pandemic. With a better understanding of policies’ relative performance, countries can more effectively invest in, and target, early nonpharmacological interventions

    Curcumin-Loaded Apotransferrin Nanoparticles Provide Efficient Cellular Uptake and Effectively Inhibit HIV-1 Replication In Vitro

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    Curcumin (diferuloylmethane) shows significant activity across a wide spectrum of conditions, but its usefulness is rather limited because of its low bioavailability. Use of nanoparticle formulations to enhance curcumin bioavailability is an emerging area of research.In the present study, curcumin-loaded apotransferrin nanoparticles (nano-curcumin) prepared by sol-oil chemistry and were characterized by electron and atomic force microscopy. Confocal studies and fluorimetric analysis revealed that these particles enter T cells through transferrin-mediated endocytosis. Nano-curcumin releases significant quantities of drug gradually over a fairly long period, ∌50% of curcumin still remaining at 6 h of time. In contrast, intracellular soluble curcumin (sol-curcumin) reaches a maximum at 2 h followed by its complete elimination by 4 h. While sol-curcumin (GI(50) = 15.6 ”M) is twice more toxic than nano-curcumin (GI(50) = 32.5 ”M), nano-curcumin (IC(50)<1.75 ”M) shows a higher anti-HIV activity compared to sol-curcumin (IC(50) = 5.1 ”M). Studies in vitro showed that nano-curcumin prominently inhibited the HIV-1 induced expression of Topo II α, IL-1ÎČ and COX-2, an effect not seen with sol-curcumin. Nano-curcumin did not affect the expression of Topoisomerase II ÎČ and TNF α. This point out that nano-curcumin affects the HIV-1 induced inflammatory responses through pathways downstream or independent of TNF α. Furthermore, nano-curcumin completely blocks the synthesis of viral cDNA in the gag region suggesting that the nano-curcumin mediated inhibition of HIV-1 replication is targeted to viral cDNA synthesis.Curcumin-loaded apotransferrin nanoparticles are highly efficacious inhibitors of HIV-1 replication in vitro and promise a high potential for clinical usefulness
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